The usefulness of 80-Hz amplitude-modulation following response (AMFR)
detected by phase spectral analysis to predict the hearing threshold
during sleep was evaluated in 20 normal adults, 8 normal children and
37 children with hearing impairment. The onset effect of tonal stimulu
s on 80-Hz steady state response was studied in normal adults during s
leep and a threshold of 80-Hz AMFR detected by phase spectral analysis
was compared with that of ABR elicited by tone pips in children durin
g sleep. Although 80-Hz AMFR is not appropriate for the assessment of
hearing in adults, it appears useful for evaluating hearing in young c
hildren during sleep. Hearing prediction by 80-Hz AMFR appears to be m
ore accurate than that by ABR elicited with tone pips. The onset effec
t of stimulus on 80-Hz AMFR with modulation depth of 95% was less than
80-Hz SSR evoked by clicks.